I built an adapter to finally calibrate/finish build of my big quad deck project. I have had it together for months, but due to instability with the mounting of my CF2 body, it was difficult to fly and some components were damaged. I have finally made a solid mount, AND acquired a chinese laser project off eBay! I can make my own frames soon, so will hopefully publish some that are purpose-built for big quad applications!

I have noticed the 4 holes in the big quad deck seem to be standardized somewhere, and have found matching sets of holes on some chassis.. but the accelerometer being used as input for the PID controller is still in the crazyflie? I would pay more for a big quad deck with this input available on it.. so that the component with the important input aspect is rigidly mounted with 4 screws, and then the crazyflie body attaches to the two m2 nylon screws.

TL;DR

The accelerometer used for input to the Crazyflie's PID when in BigQuadDeck mode is mounted to the crazyflie body, not the BQ deck, right?

The accelerometer is indeed still in the Crazyflie, the BigQuad deck 'only' breaks out connection and provide power supply to make it easier to use Crazyflie as a big quad controller.

We have a prototype, the cf-rzr, that implements everything including sensor on the main board and that has the same mounting holes as the bigquad deck. Though, we do not know yet when we will be able to release it.

Yes it will be! I am so glad to finally have a laser in my arsenal of fabrication tools.

Alright, I am glad I designed my mount accoringly, but glad to know for certain.

That looks cool! yes I am noticing the CF2 is a little bulky for permanent use but the frames have been growing so it is less of a concern. Adding more rotors might be of interest though, I am wondering how difficult it would be to make a hex or octocopter BQ deck! Perhaps the octocopter could be done with some firmware modifications and two BQ decks. Actually the same might apply to a hex copter, just two ports would be unused.

Two big quad deck on top of each-other is not going to work for sure since you will just get the same motor output on both, the brushless connector on the big quad deck are directly connected to pwm-capable pins on the Crazyflie.

The Crazyflie has a couple of pins that could be used for PWM motor output:
- There is a couple of more pin on the expantion connector that have PWM capabilities, though a new driver would need to be implemented for it
- You can use the brushed output to generate a PWM signal for a brushless controller, it requires a pull-up and is a bit hack-ish but the driver to drive PWM on the brushed connector is already done.

Later, when the Crazyflie RZR is released, it should be possible to install a RZR on a big quad deck, since the RZR is using the same PWM output for brushed and brushless, the pins used by the big quad deck can be used at the same time.

- You can use the brushed output to generate a PWM signal for a brushless controller, it requires a pull-up and is a bit hack-ish but the driver to drive PWM on the brushed connector is already done.

I like reuse of connectors someone already soldered for me

Thanks for the tips! I think I am going to take an adventure into ground vehicles for a little bit, a few of my applications require a lot of power and quadcopter uses too much. Bought two more crazyflies, I think I broke the first by putting ~17 V to the BQ deck (but not much more than a 4S pack hot off the charger?). Not ready to post about it/ask for help quite yet.

I look forward to the rzr! It could find a permanent home in my pile of gizmos. I do wish it could do more than 8 A per motor though. I guess I can always attach external ESC if I want more power, maybe that makes sense from a size/capabilities. Adding more than 4 external ESC would be really nice for a dedicated CF based drone brain! I want to build a very large quad/hex/octo with this one day.. hopefully in the next 3-5 years.

I think I'm going to cut my wings so to speak and stick to ground vehicles using the CF for now! I have two more I don't want to break. I opened a new thread regarding this question here:viewtopic.php?f=6&t=2925&p=14595#p14595